Warp stop-motion for looms.



T. A. B. CARVER.

WARP STOP MOTION FOR LOOMS.

APPLICATION FILED JUNE 8, 1912.

Patented June 23, 1914.

figgzzad ad 1? (ar UNITED STATES PATENT OFFICE.

THOMAS ALBERT BRIGGS CARVER, OI GLASGOW, SCOTLAND,

was? s'roraorron non ooms.

Specification of Letters Patent.

Patented J une 23, 1914.

Application filed June a, 1912. Serial No. 702,557.

This invention relates to an improved construction of the ordinary reedin weaving looms, whereby it is enabled to detect the breakage of athread of the warp. In

. its simplest form the reed is constructed in the ordinary way, that isby grouping the metallic dents together between pairs of wooden slats atthe two ends, the dents being separated by a cord soaked in pitch orsimilar compound so that they are electrically insulated one from theother.

According to the present invention the dents of the reeds are connectedelectrically in two groups and included in an electric circuit in suchmanner that should a dent in one group come into electric connectionwith a dent in the other group, a current will be established in thecircuit which can be used to cause or control the operation of aknockofl mechanism. Each dent is provided with a contact piece whichtends to establish this circuit by coming into engagement with anadjacent dent or a projection therefrom, but these contacts are normallyheld out of engagement either entirely by the warp threads or by a combwith insulating fingers which are withdrawn at one point of the movementof the reed so that the contacts are then held off by the warp threadsonly. Consequently should a warp thread break, the energizing orcontrolling circuit of the knock-off is established by the two adjacentdents coming into electric connection, and

section of the same taken on a plane between two dents; Figs. 4 and 5are detail yiews drawn to an enlarged scale illustrating the operationof the detectors of the modified reed of Fig. 2; Fig. 6 is adiagrammatlc view showing the subdivision of the reeds into a number ofgroups, the electrical circuits of which are controlled by a commutator,and Fig. 7 is an end view of such a commutator; and Fig. 8 is adiagrammatic view of a differentially wound relay, the operation ofwhich is controlled by the detector circuit.

As shown in Figs. 1 to 5 the dents of the reeds are connectedelectrically in two groups a and b and each group is connected in acircuit which includes a battery and preferably also a switch (not shownin the drawings) which is normally open until that period of motion ofthe loom at which the reed approaches its back position and the threadsof the warp are raised to the full opening of the shed, the switch beingthen automatically closed so that, should a warp thread be broken, thecircuit will be completed through the dents as hereinafter de scribed.

In the preferred construction of detectors of the above character eachdent a (or b) of the reed is provided with a springy projection whichmay be in the form of a tongue (1 (or b) stamped out of the dent itselfand of such length and set that if unrestrained it will touch itsneighboring dent. These springy projections are so disposed that whenthe shed is opened and the reed is in its back position and when, if thewarp is perfect, there is one thread (1 raised to the highest positionin each split 6 of the reed, the threads of the warp are then in suchposition that they interpose themselves between the springy projectingtongues a, b and the neighboring dents b, a respectively, so that thethreads themselves provide a breakage of connection between the springyprojection of one dent and the neighboring dent. The tongues'are notcentral in the dents, those in one group of dents being toward one edgeand those of the other group toward the opposite edge of the respectivedents, so that each tongue will be opposed to a solid part of itsneighboring dent, as shown in Fig. 3.

In weaving practice it is of course important to relieve the threads ofthe warp of any pressure in the reed, such as that which might beapplied by the springy projections a, 6, described working withoutfurther provision, and in order to relieve thethreads of the warp fromany undue friction, the springy projections are made of such a shape, 6.g. by having their free ends turned inward, that an insulating plate orfin er f disposed between each pair of dents 0 the warp raised to thefull opening of the shed,

. for example as that the warp is so this comb of insulating fingers ismoved in a direction lengthwise of the dents and awayfrom-the sprin s,so as to release the spring tongues a, b and permitthem, if unrestrainedby a thread of the warp, to spring into contact with the ad acent dent.

The means for periodically moving the comb may be of any suitablenature, such that of the mechanism frequently employed for actuating thep1n rails in a lappet loom, and may comprise a cam member driven fromthe main shaft of the loom and co-acting with alever 's stem operativelyconnected with the com in such a manner that when the lever system 1sintermittently actuated by the cam the comb will be withdrawn and heldout of engagement with the springs. The comb may be adapted to returnunder the action of gravity to a position wherein it presses against thesprings, or it may be positively returned by cam actuated levermechanism or other means.

The action of the detecting arrangement in the loom as described ofcourse assumes drawn into the heddles and drawn into the reed that ateach period of the loom one thread in each splitis.

raised, and the action asdescribed provides a complete warp stop motionin suchinstances. Cases in which there one thread raised in each splitat-eachperiod of the loom. may be met by connecting the I dents of thereed into suitable separate a number of,

groups, making one oup or another active or inactive by a simp e threadsin the reeds. Such an arrangement with one group a of dents, group b isdivided into I sub-groups which are "severally connected through acommutator g with the other pole of the battery 0. The commutator isprovided with contact devices-'9", which are so disposed that by"bringing the commutator any desired number of the sub-groups of thedents may be connected with or disconnected irom the battery 0.

may not be" form of commutator. in accordance with the disposition ofthe one pole of the Electrical warp stop motions are of course wellknown and simplification is aiforded by electrical action, especiallywhere contact is made, as in the a paratus described, in the immediateneighborhood of the threads themselves. 'But they are all subject to thedisadvantage that the making and breaking of the circuit in theimmediate neighborhood of the inflammable warp is dangerous on accountof the inevitable spark. In order to reduce thls danger to a minimum, anelectrical relay is provided in association with the circuit of thedetecting apparatus, so that the circuit kept open by the thread is onewhich when closed need convey only a minute amount of electrical energy,but sufiicient to control by means of the relay the establishment ofanother circuit by which the knock-off mechanism is operated.

In one form of relay suitable for the purpose (illustrated in F i 8) avery small electromagnet h is wound differentially with two coils offine wire one of which i is included in the detector circuit, while theother '21 is traversed by a current from a suitable source of justsufiicient strength. to .hold the armature against the action-of aspring or gravity, so long aswthe' detector circuit is not established.momentary closing oft-he latter, however, sufiices. to neutralize-mmmagnet andjfthereby' 'rel-ea'se"gthearmature-to 7 close thecircuitpwhich"controls-the knock ofi mechanism.

Having thus described my nvention and the best-meansI know ofcfarryingthe same into practical efiect,fI'claim-:-=- I Q1}? 1; In warp stop,motionslffor lobms, the combination of knock ofif mechanism. a normallyopen electricalcircu' controlling-themechanism, a reed comp i ing tomake. electrical-contact with an 'adja- I-y' cent. dent andthereby'efiect closure 01. 1 the electrical clrcuit', each of said fcontactsbeing" adapted to be held, out of contact with the.

adjacent dentby a warp thread interposed v between'fthe contact Land thedent? and ,un

broken. I 2.1a warp stop. motions. for looms, the

y combmatlon of knock off mechanism, arnormally open'electricalcircuit'c'ontrollingthef mechanism, a-reed comprising a number; of

dents, a, spring" contact formed integrally with each dent normallytending to make electrical contact withI-anadjacent dent and therebyeffect. closure of the electrical circuit, each of said contacts beingadapted to be held out of contact with the adjacent dent by. a warpthread interposed between the contact and the dent and'unbroke n.

3. In warp stop motions for looms, the combination of knock ofimechanism, a normally open electrical circuit controlling themechanism,a reed comprising a number of V 105, ing ',a,,number, ,oi dents,- acontact'on each dentnormally tend posed between the contact and the dentand unbroken. Y j

4. In warp stop motions for looms, the

" 1 combination of-knock'oii mechanism, a norlow mally. open'electricalcircuit controlling the mechanism, a reed comprising a plurality ofdents arranged in pairs of'groups and a contact device on each dent,each contact in a group normally tendi'nglto make electrical contactwith a neighboring dent of the felgroup of a pair so as to effectclosure of theelectrical circuit, and adapted to be held out ofcontactwith the said neighboring dent by an unbroken warp threadinterposed between the contact andthe dent.

5. In warp stop motions for looms, the combination of knock of!mechanism, a normally open electrical circuit controlling themechan1sm,'a reed comprising a plurality of dents arranged in pairs ofgroups, a contact device on each dent, each contact 111 a group normallytending to make electricallcontact with a neighboring dent of the fellowgroup of a pair so as to efiect closure of the electrical circuit, andadapted to be held out of contact with the said neighboring dent by anunbroken warp thread interposed between the contact and the dent, and acomb with insulating fingers normally disposed between eachcontactdevice and its neighboring dent and means operating during the movementof the reed'to withdraw the fingers from their normal position as andfor the purpose described.

6. In warp stop motions for looms, the combination of knock offmechanism, a normally open electrical circuit controlling the mechanism,a reed comprising a plurality of dents arranged in separate pairs ofgroups, a contact device on each dent, each contact in a group normalltending to make electrical contact with a neighboring dent of thefellow'group of a pair so as to effect closure of the electricalcircuit, and adapted to be held out of contact with the said neighboringdent by an unbroken warp thread interposed between the contact and thedent,

and means adaptedto render a desired number of the separate groups ofdents inactive with respect to the establishment of the electricalcircuit."

7. In warp stop motions for looms, the combination of knock oflmechanism, a normally open electrical circuit controlling the mechanism,a normally open electrical detector circuit, a differentially woundrelay interpolated between the detector circuit and the said firstcircuit and controlling the said first circuit, a reed comprising anumber of dents and contacts carried by each dent normally tending eachto make electrical contact with an adjacent dent so as to eflect closureof the detector circuit whereby the relay'is actuated to close the firstsaid circuit so as to operate the knock ofl" mechanism, each of saidcontacts adapted to be held out of contact with an adjacent dent by anunbroken warp thread interposed between the means and cooperating dent.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

THOMASALBERT BRIGGS CARVER. Witnesses:

WILLIAM LAMONT, ANDREW Soorr.

